1. Field of the Invention
The present disclosure relates in general, to the novel use of a Bauhinia spp. extract. More specifically, the present disclosure relates to the use of Bauhinia spp. extract as a dietary supplement for the treatment of a neurodegenerative disease.
2. Description of Related Art
Bauhinia variegata Linn. (Fabaceae) is traditionally prescribed in indigenous medicines in India. Various parts of the plant (flower buds, flowers, stem, stem bark, leaves, seeds, and roots) are used in the treatment of asthma, jaundice, tuberculosis, leprosy, and skin diseases. It has also been reported that the stem bark of B. variegata possess antitumor, anti-ulcer, and antibacterial activities. Recent studies in animal models further demonstrated that the ethanol extract of B. variegata (BVEE) exhibited significant nephroprotective effect against cisplatin-induced nephropathy, and antidiabetic activity in alloxan-induced hyperglycemic activities.
Alzheimer's disease (AD) is a progressive neurodegenerative disease and is the most prevalent form of age-related dementia. It is widely believed that the accumulation of Aβ and Tau in AD is the causative event triggering neurodegeneration and related pathogenic pathways, which together contribute to the onset and progression of AD. The truncation of Tau protein has been identified in human sporadic AD, and could also instigate the aggregation of Tau and formation of neurofibrillary tangles in AD. Accumulated evidence indicated that neprilysin (NEP) is the primary endopeptidase responsible for the clearance of Aβ and that its functional deficiency is evident during aging process and AD. Consistent with this notion, an inverse correlation is observed between NEP levels and brain Aβ loads in NEP knock-out mice (20-24). NEP has thus been regarded as the most promising pharmacological target for the development of therapeutics aiming to promote Aβ degradation as AD treatments (25-30). Furthermore, autophagic vacuoles has been shown to be the major intracellular compartment for Tau clearance. This autophagy-mediated degradation system is also believed to play a significant role in controlling the homeostasis of Aβ. Consistent with its protective role in neurons, defective autophagy has been implicated in the pathogenesis of various neurodegenerative diseases, including AD. Emerging findings suggest that autophagosomes can engulf damaged organelles and aberrant protein aggregates for the clearance of these internalized cargos following fusion with lysosomes. It is thus reasonable to speculate that autophagy-inducing agents could render neuroprotective efficacy through promoting the autophagy-mediated clearance of aberrant protein aggregates, including Aβ and Tau.
By use of a zebrafish model of tauopathy, a cell-based assay for neprilysin, and a cell-based assay for autophagy, inventors of the present disclosure unexpectedly discovered that Bauhinia spp. extract can simultaneously inhibit tauopathy-elicited neurotoxicity, enhance neprilysin activity, and induce autophagic activity, thus the present identified Bauhinia spp. extract could be used as a health food dietary supplements to improve overall memory and/or cognitive function of a patient suffering from a neurodegenerative disease.